Relation between amniotic fluid infection or cytokine levels and hearing screen failure in infants at 32 wk gestation or less

Plasma acute phase proteins as potential predictors of intra-amniotic inflammation and infection in preterm premature rupture of membranes

BACKGROUND

We aimed to investigate the potential of altered levels of various acute phase proteins (APPs) in the plasma, either used alone or in combination with ultrasound-, clinical-, and conventional blood-based tests, for predicting the risk of intra-amniotic inflammation (IAI), microbial invasion of the amniotic cavity (MIAC), histologic chorioamnionitis (HCA), and funisitis in women with preterm premature rupture of membranes (PPROM).

METHODS

A total of 195 consecutive pregnancies involving singleton women with PPROM (at 23 + 0-34 + 0 weeks) who underwent amniocentesis and from whom plasma samples were obtained at amniocentesis were retrospectively included in this study. Amniotic fluid (AF) was cultured to assess the MIAC and analyzed for interleukin (IL)-6 levels to define IAI (AF IL-6 level of ≥2.6 ng/mL). The plasma concentrations of hepcidin, mannose-binding lectin (MBL), pentraxin-2, retinol-binding protein 4 (RBP4), serum amyloid A1 (SAA1), and serpin A1 were determined using ELISA. Ultrasonographic cervical length (CL), neutrophil-to-lymphocyte ratio (NLR), and C-reactive protein levels were measured. IAI/MIAC was defined as IAI, MIAC, or both.

RESULTS

Multivariate logistic regression analyses showed the following: (1) elevated plasma levels of hepcidin and SAA1 and decreased levels of RBP4 in the plasma were independently associated with IAI/MIAC and (2) decreased plasma RBP4 levels were independently associated with funisitis; however, (3) none of the plasma APPs investigated were associated with acute HCA when adjusted for baseline covariates. Using stepwise regression analysis, noninvasive prediction models comprising plasma RBP4 levels, CL, NLR, and gestational age at sampling were proposed, which provided a good prediction of IAI/MIAC and funisitis (area under the curve: 0.80 and 0.72, respectively).

CONCLUSIONS

Hepcidin, RBP4, and SAA1 were identified as potential APP biomarkers in the plasma predictive of IAI/MIAC or funisitis in patients with PPROM. In particular, combination of these APP biomarkers with ultrasound-, clinical-, and conventional blood-based markers can significantly support the diagnosis of IAI/MIAC and funisitis.

Risk Factors for Hearing Screen Failure in a Single-Family Room Neonatal Intensive Care Unit

OBJECTIVE

 This study aimed to determine hearing screen outcomes and identify clinical and environmental risk factors for hearing screen failure in very preterm infants at a level IV single-family room (SFR) neonatal intensive care unit (NICU).

STUDY DESIGN

 We conducted a retrospective study of infants <33 weeks gestational age admitted to a level IV SFR NICU who survived to discharge and had automated auditory brainstem response results available. Demographics, antenatal and postnatal factors, and respiratory support modes and their duration were collected from the electronic medical record.

RESULTS

 Of 425 eligible infants with documented hearing screen results, 353 (83%) passed and 72 (17%) failed the hearing screen (unilateral, N = 44 [61%]; bilateral, N = 28 [39%]). Compared to infants who passed the hearing screen, infants with hearing screen failure were lower gestational age and birth weight, male sex, were screened at later postnatal and postmenstrual ages (PMAs), had lower 1- and 5-minute Apgar scores, longer duration of furosemide therapy, early hypotension, intraventricular hemorrhage (IVH) ≥Grade 3, and bronchopulmonary dysplasia (BPD) at 36 weeks PMA. Infants with hearing screen failure experienced longer exposures to invasive and noninvasive respiratory support. Heated, humidified, high flow nasal cannula >2 liters per minute exposure was significantly longer in infants with bilateral hearing screen failure (18.4 ± 18.4 d) compared to duration in infants who passed (7.4 ± 12.8 d) and those with unilateral failure (9 ± 13 d), (mean ± standard deviation [SD], p < 0.001). In the final logistic model, IVH ≥Grade 3 (odds ratio [OR] = 3.22, 95% confidence interval [CI]: 1.15-8.98, p = 0.026) and BPD (OR = 2.27, 95% CI: 1.25-4.11, p = 0.007) were the factors with the greatest risk for hearing screen failure.

CONCLUSION

 We speculate that the association of BPD with hearing screen failure may be mediated, in part, by chronic noise exposure, including from respiratory support devices. Attention to hearing protection in at-risk infants during respiratory support may mitigate the risk of hearing loss.

KEY POINTS

· NICU noise often exceeds recommended sound levels.. · Seventeen percent of infants with <33 weeks GA in SFR NICU failed hearing screenings.. · BPD and IVH are risk factors for hearing screen failure.. · Respiratory devices contribute to increased NICU noise.. · hearing protection should be considered during respiratory support..

Rescue Cerclage in Women With Acute Cervical Insufficiency and Intra-Amniotic Inflammation: A Retrospective Cohort Study

BACKGROUND

To assess the effectiveness of rescue cerclage concerning pregnancy and neonatal outcomes in women with acute cervical insufficiency (CI) complicated with intra-amniotic inflammation (IAI) compared with those managed expectantly.

METHODS

This retrospective cohort study included 87 consecutive singleton pregnant women (17-25 weeks) with acute CI who underwent amniocentesis to assess IAI. Amniotic fluid (AF) samples were assayed for interleukin-6 to define IAI (≥ 2.6 ng/mL). Primary and secondary outcomes were assessed in a subset of CI patients with IAI. The primary outcome measures were spontaneous preterm birth (SPTB) at < 28 and < 34 weeks, and the secondary outcomes were interval from sampling to delivery, neonatal survival, neonatal birth weight, and histologic and clinical chorioamnionitis. Macrolide antibiotics were prescribed depending on the type of microorganism isolated from the AF, clinically suspected IAI, and the discretion of the attending clinician.

RESULTS

IAI was identified in 65.5% (57/87) of patients with CI, of whom 73.6% (42/57) were treated with macrolide antibiotics. Among the CI patients with IAI (n = 57), 40 underwent rescue cerclage and 17 were expectantly managed. The rates of SPTBs at < 28 and < 34 weeks were significantly lower and the latency period was significantly longer in the cerclage group than in the group that was managed expectantly. The median birth weight and neonatal survival rate were significantly higher in the cerclage group than in the group that was managed expectantly. However, the rates of histologic and clinical chorioamnionitis did not differ between the groups. Multivariable analyses revealed that rescue cerclage placement and administration of macrolide antibiotics were significantly associated with a decrease in SPTBs at < 28 and < 34 weeks, prolonged gestational latency, and increased likelihood of neonatal survival, after adjusting for possible confounding parameters; however, macrolide antibiotic administration did not reach statistical significance with respect to SPTB at < 34 weeks and neonatal survival (P = 0.076 and 0.063, respectively).

CONCLUSION

Rescue cerclage along with macrolide antibiotic treatment may positively impact pregnancy and neonatal outcomes in women with CI complicated by IAI, compared with expectant management. These findings suggest the benefit of cerclage placement even in patients with CI complicated by IAI.

Characterization of Inflammation/Immune-, Acute Phase-, Extracellular Matrix-, Adhesion-, and Serine Protease-Related Proteins in the Amniotic Fluid of Women With Early Preterm Prelabor Rupture of Membranes

PROBLEM

To determine whether altered concentrations of various inflammation/immune-, acute phase-, extracellular matrix-, adhesion-, and serine protease-related proteins in the amniotic fluid (AF) are independently associated with microbial invasion of the amniotic cavity and/or intra-amniotic inflammation (MIAC/IAI), imminent spontaneous preterm delivery (SPTD; ≤7 days), and major neonatal morbidity/mortality (NMM) in women with early preterm prelabor rupture of membranes (PPROM).

METHOD OF STUDY

This was a retrospective cohort study involving 111 singleton pregnant women with PPROM (24-31 weeks) undergoing amniocentesis to diagnose MIAC/IAI. The following proteins were measured in stored AF samples by enzyme-linked immunosorbent assay (ELISA): APRIL, DKK-3, Gal-3BP, IGFBP-2, IL-8, VDBP, lumican, MMP-2, MMP-8, SPARC, TGFBI, TGF-β1, E-selectin, ICAM-5, P-selectin, haptoglobin, hepcidin, SAA1, kallistatin, and uPA.

RESULTS

Multivariate logistic regression analyses revealed that (i) elevated APRIL, IL-8, MMP-8, and TGFBI levels in the AF, reduced lumican and SPARC levels in the AF, and high percentages of samples above the lower limit of quantification for AF TGF-β1 and uPA were significantly associated with MIAC/IAI; (ii) elevated AF levels of IL-8 and MMP-8 were significantly associated with SPTD within 7 days; and (iii) elevated AF IL-6 levels were significantly associated with increased risk for major NMM, when adjusted for baseline covariates.

CONCLUSION

ECM (lumican, SPRAC, TGFBI, and TGF-β1)- and serine protease (uPA)-associated proteins in the AF are involved in the regulation of the host response to infection/inflammation in the amniotic cavity, whereas AF inflammation (IL-8, MMP-8, and IL-6)-associated mediators are implicated in the development of preterm parturition and major NMM in early PPROM.

Plasma Kallistatin and Progranulin as Predictive Biomarkers of Intraamniotic Inflammation, Microbial Invasion of the Amniotic Cavity, and Composite Neonatal Morbidity/Mortality in Women With Preterm Premature Rupture of Membranes

PROBLEM

To explore the clinical utility of nine inflammatory immune-, adhesion-, and extracellular matrix-related mediators in the plasma for predicting intraamniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) and composite neonatal morbidity and/or mortality (CNMM) in women with preterm premature rupture of membranes (PPROM) when used alone or in combination with conventional blood-, ultrasound-, and clinical-based factors.

METHODS OF STUDY

This retrospective cohort comprised 173 singleton pregnant women with PPROM (24 + 0 - 33 + 6 weeks), who underwent amniocentesis. Amniotic fluid was cultured for microorganisms and assayed for IL-6 levels. Plasma levels of AFP, CXCL14, E-selectin, Gal-3BP, kallistatin, progranulin, P-selectin, TGFBI, and VDBP were determined by ELISA. Ultrasonographic cervical length (CL) and neutrophil-to-lymphocyte ratio (NLR) were measured.

RESULTS

Multivariate logistic regression analyses revealed significant associations between (i) decreased plasma kallistatin levels and IAI/MIAC and (ii) decreased plasma progranulin levels and increased CNMM risk after adjusting for baseline variables (e.g., gestational age at sampling [or delivery] and parity). Using stepwise regression analysis, noninvasive prediction models for IAI/MIAC and CNMM risks were developed, which included plasma progranulin levels, NLR, CL, and gestational age at sampling, and provided a good prediction of the corresponding endpoints (area under the curve: 0.79 and 0.87, respectively).

CONCLUSIONS

Kallistatin and progranulin are potentially valuable plasma biomarkers for predicting IAI/MIAC and CNMM in women with PPROM. Particularly, the combination of these plasma biomarkers with conventional blood-, ultrasound-, and clinical-based factors can significantly support the diagnosis of IAI/MIAC and CNMM.

Predictive potential of various plasma inflammation-, angiogenesis-, and extracellular matrix remodeling-associated mediators for intra-amniotic inflammation and/or microbial invasion of the amniotic cavity in preterm labor

PURPOSE

To determine whether various inflammatory-, angiogenic/anti-angiogenic-, and extracellular matrix remodeling-associated proteins in plasma, alone or in combination with conventional blood-based markers, can predict intra-amniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) in women with spontaneous preterm labor (PTL).

METHODS

A total of 193 singleton pregnant women with PTL (23-33 weeks) were included in this retrospective cohort study. Plasma samples were obtained at the time of amniocentesis. Amniotic fluid (AF) was cultured for microorganism detection and consequent MIAC diagnosis. IL-6 levels were determined in AF and used to identify IAI (AF IL-6 ≥ 2.6 ng/mL). Endostatin, haptoglobin, IGFBP-2/3, LBP, M-CSF, MMP-2/8, pentraxin 3, PlGF, S100A8/A9, and VEGFR-1 levels were assayed in plasma samples by ELISA. CRP levels and neutrophil-to-lymphocyte ratio (NLR) were measured.

RESULTS

Plasma LBP, MMP-8, and S100A8/A9 levels, CRP levels, and NLR were significantly higher, and plasma IGFBP-2 and MMP-2 levels were significantly lower in women with IAI/MIAC than in those without this condition, whereas no baseline variables differed significantly between the two groups. Using a stepwise regression analysis, a noninvasive prediction model for IAI/MIAC was developed, which included plasma LBP, MMP-2, and MMP-8 levels (area under the curve [AUC], 0.785). The AUC for this prediction model was significantly or borderline greater than that of any single factor included in the model.

CONCLUSIONS

IGFBP-2, LBP, MMP-2, MMP-8, and S100A8/A9 may represent valuable plasma biomarkers for predicting IAI/MIAC in women with PTL. Combination of LBP, MMP-2, and MMP-8 expression data can significantly improve the predictive potential for IAI/MIAC.

Potential of plasma inflammatory and angiogenic mediators for predicting spontaneous preterm delivery, intraamniotic infection/inflammation, and composite neonatal morbidity/mortality in women with early preterm premature rupture of membranes

PROBLEM

To assess the potential of five inflammatory and six angiogenic/antiangiogenic plasma proteins for predicting imminent spontaneous preterm delivery (SPTD; ≤14 days of sampling), microbial invasion of the amniotic cavity and/or intraamniotic inflammation (MIAC/IAI), and composite neonatal morbidity and mortality (CNMM) in women with early preterm premature rupture of membranes (PPROM).

METHODS OF STUDY

This retrospective cohort study included 76 singleton pregnant women with early PPROM (23-30 weeks). Amniotic fluid obtained via amniocentesis was cultured for microorganism detection and assayed for interleukin-6 to define IAI (≥2.6 ng/mL). Plasma C4a, endoglin, endostatin, IGFBP-1, IGFBP-2, MMP-9, PlGF, S100A8, S100A9, S100 A8/A9, and VEGFR-1 levels were determined using ELISA.

RESULTS

Multivariate logistic regression analyses revealed significant associations between (i) high levels of plasma S100A8/A9, SPTD ≤14 days after sampling, and shorter sampling-to-delivery intervals; (ii) elevated plasma MMP-9, S100A9, and S100A8/A9 levels and MIAC/IAI, and (iii) decreased plasma endoglin levels and increased CNMM risk, while adjusting for gestational age at sampling (or delivery) and tocolytic use. The area under the curves of the aforementioned proteins ranged from 0.655 to 0.731 for each outcome. Notably, the SPTD risk increased significantly with increasing plasma S100A8/A9 levels (P for trend < .05).

CONCLUSIONS

Plasma S100A8/A9, MMP-9, S100A9, and endoglin may represent valuable biomarkers associated with SPTD, MIAC/IAI, and CNMM in women with early PPROM. Owing to their less invasive nature, repeatability, and fair-to-moderate diagnostic accuracy, these biomarkers may contribute to risk stratification of PPROM-related complications in the clinical setting.

Inflammatory biomarkers in the cervicovaginal fluid to identify histologic chorioamnionitis and funisitis in women with preterm labor

OBJECTIVE

We investigated the association between altered levels of inflammatory proteins in the cervicovaginal fluid (CVF) and acute histologic chorioamnionitis (HCA) and funisitis in women with preterm labor (PTL).

METHODS

In this study, a total of 134 consecutive singleton pregnant women with PTL (at 23+0-34+0 weeks) who delivered preterm (at  < 37 weeks) and from whom CVF samples were collected at admission were retrospectively enrolled. The CVF levels of haptoglobin, interleukin-6/8, kallistatin, lipocalin-2, matrix metalloproteinase (MMP)-8, resistin, S100 calcium-binding protein A8, and serpin A1 were determined using enzyme-linked immunosorbent assay. The placentas were histologically analyzed after delivery.

RESULTS

Multiple logistic regression analyses showed significant associations between elevated CVF interleukin-8 and resistin levels and acute HCA after adjusting for baseline covariates (e.g., gestational age at sampling). CVF haptoglobin, interleukin-6/8, kallistatin, MMP-8, and resistin levels were significantly higher in women with funisitis than in those without, whereas the baseline covariates were similar between the two groups (P > 0.1). The area under the receiver operating characteristic curves of the aforementioned biomarkers ranged from 0.61 to 0.77 regarding each outcome. Notably, HCA risk significantly increased with increasing CVF levels of interleukin-8 and resistin (P for trend  < 0.05).

CONCLUSIONS

Haptoglobin, interleukin-6/8, kallistatin, MMP-8, and resistin were identified as potential inflammatory CVF biomarkers predictive of acute HCA and funisitis in women with PTL. Moreover, the risk severity of acute HCA may be associated with the degree of the inflammatory response in the CVF (particularly based on interleukin-8 levels).

Cord blood transforming growth factor-β-induced as predictive biomarker of retinopathy of prematurity in preterm infants

PURPOSE

To determine whether 14 inflammation-, angiogenesis-, and adhesion-related proteins in cord blood (CB), alone or in combination with conventional perinatal factors, could predict retinopathy of prematurity (ROP) in preterm infants.

METHODS

Data from 111 preterm infants (born at ≤ 32.0 weeks) were retrospectively reviewed. The levels of endoglin, E-selectin, HSP70, IGFBP-3/4, LBP, lipocaline-2, M-CSFR, MIP-1α, pentraxin 3, P-selectin, TGFBI, TGF-β1, and TNFR2 were assessed in stored CB samples collected at birth using ELISA kits. The primary endpoints included severe ROP (≥ stage 3) and type 1 ROP requiring treatment.

RESULTS

ROP was diagnosed in 29 infants (26.1%), among whom 14 (12.6%) had severe ROP and seven (6.3%) had type 1 ROP. Multivariate logistic regression showed that decreased CB TGFBI levels were significantly associated with severe ROP and type 1 ROP after adjusting for gestational age at birth. Stepwise regression analysis allowed to design prediction models with good accuracy, which comprised low CB TGFBI levels and low birth weight (BW) as predictors for severe ROP (area under the curve [AUC] = 0.888), and low CB endoglin levels and low BW as predictors for type 1 ROP (AUC = 0.950). None of the other CB proteins evaluated were found to be associated with severe ROP or type 1 ROP.

CONCLUSIONS

Low CB TGFBI levels are associated with severe ROP and type 1 ROP, independently of gestational age. Moreover, combined predictive models based on CB TGFBI and endoglin levels, along with BW data, may act as good indicators at birth for the neonatal risk of ROP progression.

Degree of expression of inflammatory proteins in the amniotic cavity, but not prior obstetric history, is associated with the risk severity for spontaneous preterm birth after rescue cerclage for cervical insufficiency

PROBLEM

To examine whether the severity of spontaneous preterm birth (SPTB) risk after rescue cerclage for acute cervical insufficiency (CI) is linked to the degree of inflammatory response in the amniotic fluid (AF) based on the concentrations of various inflammatory proteins and prior obstetric history.

METHOD OF STUDY

We conducted a retrospective cohort study of 65 singleton pregnant women (17-25 weeks) who underwent rescue cerclage following the diagnosis of acute CI and were subjected to amniocentesis. EN-RAGE, IL-6, IL-8, and IP-10 as inflammatory mediators and kallistatin, MMP-2/8, and uPA as extracellular matrix remodeling-related molecules were assayed in the AF using ELISA. The level of each inflammatory mediator was divided into quartiles.

RESULTS

Intra-amniotic inflammation (IAI; AF IL-6 level ≥2.6 ng/mL) was independently associated with SPTB after cerclage placement. The odds of SPTB at < 32 weeks, even after adjusting for confounders, increased significantly with each increasing quartile of baseline AF levels for each inflammatory mediator (p for trend < .05). Kaplan-Meier survival curves showed that the cerclage-to-delivery intervals were significantly shorter as the quartiles of AF EN-RAGE and MMP-8 increased (log-rank test, p < .01 each). Neither previous term birth nor prior PTB was associated with SPTB risk or cerclage-to-delivery interval after rescue cerclage. Multiparous women who experience CI after term birth showed significantly elevated levels of MMP-8 and reduced kallistatin levels in the AF.

CONCLUSION

In patients with CI, SPTB risk (especially risk severity) after rescue cerclage is associated with the degree of the inflammatory response in AF as well as the presence of IAI but not with prior obstetric history.

Extracellular matrix-related and serine protease proteins in the amniotic fluid of women with early preterm labor: Association with spontaneous preterm birth, intra-amniotic inflammation, and microbial invasion of the amniotic cavity

PROBLEM

We aimed to determine whether altered levels of various extracellular matrix (ECM)-related and serine protease proteins in the amniotic fluid (AF) are associated with imminent spontaneous preterm birth (SPTB; ≤7 days) and intra-amniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) in women with early preterm labor (PTL).

METHOD OF STUDY

This retrospective cohort study included 252 women with singleton pregnancies undergoing transabdominal amniocentesis who demonstrated PTL (24-31 weeks). The AF was cultured for microorganism detection to characterize MIAC. IL-6 concentrations were determined in the AF samples to identify IAI (≥2.6 ng/mL). The following mediators were measured in the AF samples using ELISA: kallistatin, lumican, MMP-2, SPARC, TGFBI, and uPA.

RESULTS

Kallistatin, MMP-2, TGFBI, and uPA levels were significantly higher and SPARC and lumican levels were significantly lower in the AF of women who spontaneously delivered within 7 days than in the AF of those who delivered after 7 days; the levels of the first five mediators were independent of baseline clinical variables. In the multivariate analysis, elevated levels of kallistatin, MMP-2, TGFBI, and uPA and low levels of lumican and SPARC in the AF were significantly associated with IAI/MIAC and MIAC, even after adjusting for the gestational age at sampling. The areas under the curves of the aforementioned biomarkers ranged from 0.58 to 0.87 for the diagnoses of each of the corresponding endpoints.

CONCLUSION

ECM-related (SPARC, TGFBI, lumican, and MMP-2) and serine protease (kallistatin and uPA) proteins in the AF are involved in preterm parturition and regulation of intra-amniotic inflammatory/infectious responses in PTL.

Proteomic analysis of plasma to identify novel biomarkers for intra-amniotic infection and/or inflammation in preterm premature rupture of membranes

To identify potential plasma biomarkers associated with microbial invasion of the amniotic cavity (MIAC) and/or intraamniotic inflammation (IAI) in women with preterm premature rupture of membranes (PPROM). This retrospective cohort study included 182 singleton pregnant women with PPROM (23-33 weeks) who underwent amniocentesis. Plasma samples; all subjects were chosen from these participants and were analyzed using label-free liquid chromatography-tandem mass spectrometry for proteome profiling using a nested case-control study design (cases with MIAC/IAI vs. non-MIAC/IAI controls [n = 9 each]). Three identified target molecules for MIAC/IAI were further verified by ELISA in the study cohort (n = 182). Shotgun proteomic analysis revealed 17 differentially expressed proteins (P < 0.05) in the plasma of MIAC/IAI cases. In particular, the levels of FCGR3A and haptoglobin, but not LRP1, were found to be increased in the plasma of patients with MIAC, IAI, and both MIAC/IAI compared with those without these conditions. Moreover, these differences remained significant after adjusting for gestational age at sampling. The area under the curves of plasma FCGR3A and haptoglobin ranged within 0.59-0.65 with respect to each of the three outcome measures. Plasma FCGR3A and haptoglobin were identified as potential independent biomarkers for less-invasively detecting MIAC/IAI in women with PPROM.

Plasma IGFBP-1, Fas, kallistatin, and P-selectin as predictive biomarkers of histologic chorioamnionitis and associated intra-amniotic infection in women with preterm labor

PROBLEM

To determine whether altered levels of 13 plasma biomarkers, alone or in combination, could be independently associated with histologic chorioamnionitis (HCA) and microbial-associated HCA (defined as the presence of HCA along with microbial invasion) in women with preterm labor (PTL).

METHODS OF STUDY

This was a retrospective cohort study involving 77 singleton pregnant women with PTL (23-34 gestational weeks) who delivered within 96 h of plasma and amniotic fluid (AF) sampling. DKK-3, E-selectin, Fas, haptoglobin, IGFBP-1, kallistatin, MMP-2, MMP-8, pentraxin 3, progranulin, P-selectin, SAA4, and TGFBI levels were assayed in plasma samples by ELISA. AF obtained via amniocentesis was used for microorganism identification.

RESULTS

Multiple logistic regression analyses revealed significant associations between low plasma IGFBP-1 levels and acute HCA, and between low plasma Fas and kallistatin levels, and elevated plasma P-selectin levels and microbial-associated HCA (all p < .05), after adjusting for gestational age. Using a stepwise regression procedure, a multi-biomarker panel for microbial-associated HCA was developed, which included plasma MMP-2, kallistatin, and P-selectin levels (area under the curve [AUC], .867). The AUC for this three-marker panel was significantly or borderline significantly greater than that of any single variable included in the panel. However, a predictive model for acute HCA could not be developed because only one variable (MMP-2) was selected.

CONCLUSIONS

These findings demonstrate that IGFBP-1, Fas, kallistatin, and P-selectin are associated with acute HCA and microbial-associated HCA in women with PTL. Their combined use can significantly improve the diagnostic ability for the detection of microbial-associated HCA.

Plasma proteomic analysis to identify potential biomarkers of histologic chorioamnionitis in women with preterm premature rupture of membranes

Introduction

To identify potential biomarkers in the plasma that could predict histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM), using shotgun and targeted proteomic analyses.

Methods

This retrospective cohort study included 78 singleton pregnant women with PPROM (24–34 gestational weeks) who delivered within 96 h of blood sampling. Maternal plasma samples were analyzed by label-free liquid chromatography-tandem mass spectrometry for proteome profiling in a nested case-control study design (HCA cases vs. non-HCA controls [n = 9 each]). Differential expression of 12 candidate proteins was assessed by multiple reaction monitoring-mass spectrometry (MRM-MS) analysis in individual plasma samples from cases and controls matched by gestational age at sampling (n = 40, cohort 1). A validation study was further performed in an independent study group (n = 38, cohort 2) using ELISA and turbidimetric immunoassay for three differentially expressed proteins.

Results

Shotgun proteomics analyses yielded 18 proteins that were differentially expressed (P < 0.05) between HCA cases and non-HCA controls. MRM-MS analysis of 12 differentially expressed proteins further revealed that the CRP, C4A, and SAA4 levels were significantly increased in women with HCA. A multi-marker panel comprising plasma SAA4 and C4A showed enhanced potential for differentiating HCA from non-HCA women (area under the curve = 0.899). Additional validation of these findings by ELISA assays revealed that the CRP levels were significantly higher in women with HCA than in those without HCA, whereas the plasma levels of C4A and SAA4 did not significantly differ between the two groups.

Conclusions

Plasma C4A, SAA4, and CRP were identified as potential biomarkers for detecting HCA in women with PPROM, based on targeted and shotgun proteomic analyses, showing good accuracy when used as a combined dual-biomarker panel (C4A and SAA4). Nevertheless, ELISA validation of these proteins, except for CRP, may not yield clinically useful markers for predicting HCA.

High-throughput analysis of amniotic fluid proteins associated with histological chorioamnionitis in preterm premature rupture of membranes using an antibody-based microarray

PROBLEM

To identify potential proteins in the amniotic fluid (AF) that may be associated with histologic chorioamnionitis (HCA) in patients with preterm premature rupture of membranes (PPROM) using antibody-based microarray analysis.

METHOD OF STUDY

This was a retrospective cohort study involving 100 singleton pregnant women with PPROM at 24-34 weeks who underwent amniocentesis and delivered within 120 h of amniocentesis. First, the AF proteomes of 15 patients with PPROM and HCA were compared with those of 15 gestational age-matched patients without HCA using a protein microarray. Next, 12 candidate proteins associated with HCA were further validated in 100 consecutive patients with PPROM by ELISA.

RESULTS

Of 507 proteins assessed in the microarray analysis, 46 showed significant intergroup differences. Further quantification confirmed that the levels of EN-RAGE, IL-6, MMP-9, TNFR2, SPARC, TSP2, and uPA were higher in the AF of PPROM patients with HCA than in those without. Multivariate analyses also showed that elevated AF EN-RAGE, IL-6, MMP-9, and TNFR2 levels were independently associated with HCA when adjusted for baseline variables. The frequency of the highest quartile of the aforementioned proteins significantly increased as the total grade of HCA increased; the risk of HCA significantly increased with increasing AF levels of each protein (P for trend < .001).

CONCLUSIONS

Using protein-antibody microarray technology, we discovered several potential AF proteins (EN-RAGE, IL-6, MMP-9, and TNFR2) independently associated with HCA in patients with PPROM. Furthermore, we demonstrated a direct correlation between the gradation of the intra-amniotic inflammatory response and HCA severity.

Plasma E-selectin and kallistatin as predictive markers of histologic chorioamnionitis in women with preterm premature rupture of membranes

PROBLEM

We aimed to assess the predictive potential of 12 plasma biomarkers to predict acute histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM) and to develop multi-biomarker panels based on these biomarkers in combination with widely used conventional laboratory markers.

METHOD OF STUDY

This was a retrospective cohort study involving 81 singleton pregnant women (24-34 weeks of gestation) who delivered within 96 h of blood sampling. White blood cell (WBC) count, differential counts, and C-reactive protein (CRP) levels were measured at admission. The levels of DKK-3, Fas, haptoglobin, IGFBP-2, kallistatin, MIP-1α, MMP-2, MMP-8, pentraxin 3, progranulin, E-selectin, and P-selectin were evaluated by ELISA using stored plasma samples. The primary outcome measure was acute HCA.

RESULTS

Multivariate analyses showed that low plasma E-selectin and kallistatin levels were independently associated with HCA occurrence after adjusting for gestational age. Using a stepwise regression analysis, a multi-biomarker panel comprising plasma E-selectin, serum CRP, and WBC was developed, which provided a good prediction of acute HCA in women with PPROM (area under the curve [AUC], 0.899), with a significantly higher AUC than that of any single variable included in the panel (P<0.05). The plasma levels of DKK-3, Fas, haptoglobin, IGFBP-2, MIP-1α, MMP-2, MMP-8, pentraxin 3, and P-selectin were not significantly associated with HCA occurrence.

CONCLUSIONS

This study identified E-selectin and kallistatin as potential plasma biomarkers associated with acute HCA in women with PPROM. Their combined analysis with serum CRP and WBC counts significantly improved acute HCA diagnosis. This article is protected by copyright. All rights reserved.

Is chorioamnionitis associated with hearing impairment in preterm infants? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

It has been reported that chorioamnionitis (CA) could increase the risk of hearing impairment in premature infants, but results are inconsistent. A meta-analysis was performed to systematically evaluate the relationship between CA and hearing impairment in premature infants.

MATERIAL AND METHODS

Search in PubMed, Embase, Cochrane Library from their inception to May 2020. We concluded all cohort and case-control studies which explored the associations between CA and hearing impairment in preterm infants. Pregnant women with other infections besides CA were excluded. PRISMA guidelines were followed. Fixed-and random-effects models were used, depending on heterogeneity. And we performed to calculate odds ratio (ORs), and 95% CIs using fixed-effects models.

RESULTS

Seven studies involving 4134 premature infants were included. There was non-significant association between CA and hearing impairment (adjusted OR 1.43, 95% CI 0.99 to 2.04, P = 0.05; heterogeneity: I² = 13%, P = 0.33).

CONCLUSION

This article concludes that CA is not a risk factor for hearing impairment in premature infants, but most of the current studies are retrospective studies with low intensity and lack of high-quality articles to discuss it.

Change to Hearing Loss-Related Risks and Screening in Preterm Infants

Hearing loss is one of the most common congenital defects in infancy; it increases speech and language delays and adversely affects academic achievement and socialemotional development. The risk of hearing loss in premature infants is higher than that in normal newborns, and because of the fragility of the auditory nervous system, it is more vulnerable to different risk factors. The hearing screening guidelines in current use were proposed by the American Academy of Pediatrics and updated in 2007, but there are no uniform guidelines for hearing screening in preterm infants. This review focuses on the risk factors related to hearing loss in premature infants, hearing screening strategies, and reasons for failure. The aim is to provide a more comprehensive understanding of hearing development in preterm infants to achieve early detection and early intervention. At the same time, attention should be paid to delayed auditory maturation in preterm infants to avoid excessive intervention. KEY POINTS: · Hearing loss is very common in infancy, especially in premature infants.. · Genetic factors, infection, hyperbilirubinemia, drugs, and noise are the main causes.. · We should pay attention to the delayed hearing maturity of premature infants and avoid excessive intervention..

Maternal Plasma and Amniotic Fluid LBP, Pentraxin 3, Resistin, and IGFBP-3: Biomarkers of Microbial Invasion of Amniotic Cavity and/or Intra-amniotic Inflammation in Women with Preterm Premature Rupture of Membranes

BACKGROUND

We sought to determine whether lipopolysaccharide binding protein (LBP), pentraxin 3, resistin, and insulin-like growth factor binding protein (IGFBP)-3 in plasma and amniotic fluid (AF) can predict microbial invasion of the amniotic cavity (MIAC), intra-amniotic inflammation (IAI), and microbial-associated IAI in women with preterm premature rupture of membranes (PPROM).

METHODS

This was a retrospective cohort study involving 168 singleton pregnant women with PPROM. AF obtained via amniocentesis was cultured and assayed for interleukin (IL)-6 to define IAI and for IL-8 to compare with AF biomarkers. Plasma samples were collected at the time of amniocentesis, and C-reactive protein (CRP) levels in serum were compared with plasma biomarkers. The stored plasma and AF samples were assayed for LBP, pentraxin 3 (PTX3), resistin, and IGFBP-3 by ELISA.

RESULTS

Multivariate logistic regression analysis revealed that: 1) elevated plasma and AF levels of LBP were independently associated with increased risks of MIAC, IAI, and microbial-associated IAI; 2) elevated AF, but not plasma, PTX3, and resistin levels were independently associated with increased risks of MIAC, IAI, and microbial-associated IAI; 3) decreased IGFBP-3 levels in the plasma were independently associated with only IAI, whereas those in the AF were associated with only microbial-associated IAI. Among the tested biomarkers, AF PTX3 and resistin had the highest predictive performance for MIAC, IAI, and microbial-associated IAI (area under the curves [AUC] = 0.85-0.95), which is similar to the performance of AF IL-8. The AUCs of the plasma LBP and IGFBP-3 were similar to that of serum CRP with respect to IAI.

CONCLUSION

Maternal plasma LBP and IGFBP-3 are potential biomarkers for the non-invasive identification of IAI in women with PPROM, with a similar accuracy to the serum CRP level. AF LBP, PTX3, resistin, and IGFBP-3 may be involved in the intra-amniotic inflammatory responses in PPROM complicated by MIAC.

Identifying potential biomarkers related to pre-term delivery by proteomic analysis of amniotic fluid

We sought to identify biomarkers in the amniotic fluid (AF) and specific signaling pathways related to spontaneous preterm delivery (SPTD, < 34 weeks) in women with preterm labor (PTL) without intra-uterine infection/inflammation (IUI). This was a retrospective cohort study of a total of 139 PTL women with singleton gestation (24 + 0 to 32 + 6 weeks) who underwent amniocentesis and who displayed no evidence of IUI. A nested case-control was conducted using pooled AF samples (n = 20) analyzed via label-free liquid chromatography-tandem mass spectrometry. In the total cohort, an ELISA validation study was performed for seven candidate proteins of interest. Proteomic analysis identified 77 differentially expressed proteins (DEPs, P < 0.05) in the AF from SPTD cases compared to term delivery controls. ELISA validation confirmed that women who had an SPTD before 34 weeks had significantly independently lower levels of VEGFR-1 and higher levels of lipocalin-2 and the Fc fragment of IgG binding protein in the AF. Five principle pathways associated with the 77 DEPs were identified, including glycolysis, gluconeogenesis, and iron homeostasis. The proteomic analysis data of AFs from women with PTL identified several novel biomarkers and specific protein pathways related to SPTD in the absence of IUI.

Inflammatory and Angiogenic Mediators in Amniotic Fluid Are Associated With the Development of Retinopathy of Prematurity in Preterm Infants

Purpose

To investigate whether elevated levels of inflammatory/angiogenic and growth mediators in amniotic fluid (AF) and the presence of intra-amniotic infection are associated with the occurrence and progression of retinopathy of prematurity (ROP) in preterm infants.

Methods

This retrospective cohort study included 175 premature singleton infants who were born between 23+0 and 32+0 weeks. AF obtained via amniocentesis was cultured, and endoglin, endostatin, insulin-like growth factor-binding protein (IGFBP)-2, IGFBP-3, IGFBP-4, IL-6, IL-8, matrix metalloproteinase-8, matrix metalloproteinase-9, and vascular endothelial growth factor receptor-1 levels were assayed by ELISA. The primary outcome measures included the occurrence of any stage ROP, severe ROP (stage ≥3), and vision-threatening type 1 ROP requiring treatment.

Results

Multiple logistic regression analyses revealed that there are significant associations between elevated AF endoglin levels and ROP occurrence; between elevated AF endoglin, endostatin, and IGFBP-2 levels and severe ROP; and between high AF endoglin, IL-6, and IL-8 levels and vision-threatening ROP requiring treatment, after adjusting for potential postnatal confounders. Using stepwise regression analyses, antenatal prediction models based on these AF biomarkers and prenatal factors were developed for the ROP outcomes, which had good discriminatory power (area under the curves, 0.731-0.863). However, we found that intra-amniotic infection is not associated with ROP occurrence and progression.

Conclusions

Elevated levels of inflammatory (IL-6 and IL-8) and angiogenic (endoglin and IGFBP-2) mediators in the AF, but not the presence of intra-amniotic infection, are independently associated with the occurrence and progression of ROP in preterm infants. These findings suggest that the pathophysiologic events that predispose preterm neonates to ROP may begin before delivery.

A Protein Microarray Analysis of Plasma Proteins for the Prediction of Spontaneous Preterm Delivery in Women with Preterm Labor

We aimed to identify novel biomarkers in maternal plasma that predict spontaneous preterm delivery (SPTD) in women with preterm labor (PTL) using an antibody microarray and to develop the best prediction model for SPTD based on these biomarkers in combination with clinical and ultrasound factors. This retrospective cohort study included 215 women with singleton pregnancies and PTL (23-33 weeks) who gave plasma samples. In a nested case-control study design, plasma proteomes from SPTD (case subjects, n = 15) and term delivery (control subjects, n = 15) groups were differentially profiled using a membrane-based antibody microarray. Six candidate biomarkers of interest were validated by enzyme-linked immunosorbent assay (ELISA) in the total cohort (n = 215). Cervical lengths were also measured. The primary outcome measure was SPTD within 48 h after sampling. Twenty of the molecules studied displayed significant intergroup differences. Validation by ELISA confirmed significantly higher levels of plasma endostatin and lipopolysaccharide binding protein (LBP) in women who had SPTD within 48 h than in those delivering after 48 h. However, plasma macrophage inflammatory protein (MIP)-1α levels were significantly lower in women who delivered within 48 h. A combined model was developed to predict SPTD within 48 h using a stepwise regression procedure, which included plasma endostatin and LBP levels, nulliparity, and cervical length (area under the curve = 0.920). Plasma LBP, endostatin, and MIP-1α are potential new biomarkers for predicting imminent SPTD and a combined noninvasive model based on these biomarkers and clinical and ultrasound factors can accurately predict imminent SPTD in women with PTL.

Immune and Inflammatory Proteins in Cord Blood as Predictive Biomarkers of Retinopathy of Prematurity in Preterm Infants

Purpose

To determine whether elevated levels of immune/inflammatory proteins in cord blood, alone or in combination with conventional clinical parameters, can predict the occurrence and progression of retinopathy of prematurity (ROP) in preterm infants.

Methods

This was a retrospective cohort study of 110 premature singleton infants who were born at ≤32.0 weeks. Cord plasma at birth was assayed for interleukin-6, C3a, C5a, matrix metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitor of metalloproteinase-1, macrophage colony-stimulating factor, endostatin, a proliferation-inducing ligand, insulin-like growth factor-binding protein-1 (IGFBP-1), IGFBP-2, and calcium-binding protein A8/A9 complex levels. The primary outcome measures were the occurrence of any stage ROP, severe ROP (>stage 3), and vision-threatening type 1 ROP requiring laser treatment.

Results

ROP was diagnosed in 30 of 110 infants (27.3%), including 14 (12.7%) with severe ROP. Laser treatment was performed on 7 infants (6.4%). Multiple logistic regression analyses indicated that elevated levels of cord plasma IL-6 were significantly associated with severe ROP, whereas elevated levels of cord plasma C5a were significantly associated with ROP laser treatments. However, none of the proteins measured in the cord plasma were associated with ROP occurrence. Using a stepwise regression procedure, we developed a combined prediction model, which included high cord plasma IL-6 levels and low birth weight for severe ROP (area under the curve [AUC], 0.840), and high cord plasma C5a levels and low birth weight for laser treatment (AUC, 0.884).

Conclusions

Elevated levels of cord plasma IL-6 and C5a could be used as independent markers to predict severe ROP and laser treatment, respectively, with combined models predicting ROP progression with good accuracy.

Cervicovaginal Fluid Protein Microarray for Detection of Microbial Invasion of the Amniotic Cavity in Preterm Labor

We aimed to identify cervicovaginal fluid (CVF) biomarkers that can detect microbial invasion of the amniotic cavity (MIAC) in women with preterm labor (PTL) with an antibody microarray and to develop the best combined model for detection of MIAC using these biomarkers in combination with conventional clinical variables. This retrospective cohort study included 168 singleton pregnant women with PTL (23-34 weeks) who underwent amniocentesis. AF was cultured, and CVF samples were obtained at the time of amniocentesis. An antibody microarray was used to analyze the CVF proteome (n = 40). The validation of four candidate biomarkers of interest was performed by enzyme-linked immunosorbent assay (ELISA) in the final cohort (n = 168). For comparison with candidate markers, CVF IL-6 concentration was also measured. Twenty-seven molecules studied exhibited intergroup differences. Validation by ELISA confirmed significantly higher levels of CVF DKK3, M-CSF, and TIMP-1, but not of IGFBP-2, independent of gestational age, in CVF of women with MIAC. The area under the curve (AUC) of DKK3, M-CSF, and TIMP-1 from CVF was not significantly different from the AUC of IL-6 from CVF for detecting MIAC in women with PTL. By using a stepwise regression analysis, a combined detection model was developed, which included the CVF M-CSF, TIMP-1, and gestational age at sampling (AUC = 0.823). An antibody microarray identified useful biomarkers (DKK3, M-CSF, and TIMP-1) in CVF for detection of MIAC, and a combined model including these biomarkers and gestational age can accurately detect MIAC in women with PTL.

Inflammatory and Immune Proteins in Umbilical Cord Blood: Association with Hearing Screening Test Failure in Preterm Neonates

Objective

We aimed to determine whether elevated levels of various inflammatory and immune proteins in umbilical cord blood are associated with an increased risk of newborn hearing screening (NHS) test failure in preterm neonates.

Methods

This retrospective cohort study included 127 premature singleton infants who were born at ≤33.6 weeks. Umbilical cord plasma at birth was assayed for interleukin (IL)-6, complement C3a and C5a, matrix metalloproteinase (MMP)-9, macrophage colony-stimulating factor (M-CSF), and endostatin levels using ELISA kits. Neonatal blood C-reactive protein (CRP) levels were measured within 2 hours of birth. The primary outcome measure was a uni- or bilateral refer result on an NHS test. Univariate and multivariate analyses were applied.

Results

Fifteen (11.8%) infants failed the NHS test. In the univariate analyses, high IL-6 and low C3a levels in umbilical cord plasma, funisitis, and an elevated CRP level (>5 mg/L) in the immediate postnatal period were significantly associated with NHS test failure. However, the levels of umbilical cord plasma MMP-9, C5a, M-CSF, and endostatin were not significantly different between infants who passed and those who failed the NHS test. Multiple logistic regression analyses indicated that elevated umbilical cord plasma C3a levels were independently associated with a reduced risk of NHS test failure, whereas elevated levels of umbilical cord plasma IL-6 and high CRP levels in the immediate postnatal period were significantly associated with NHS test failure.

Conclusions

Our data demonstrated that in preterm neonates, a systemic fetal inflammatory response reflected by umbilical cord plasma IL-6 and immediate postnatal CRP levels may contribute to the risk for NHS test failure, whereas the changes in complement activation fragments initiated in utero may have protective effect of hearing screen failure.